The Immunogen Production and Immunizations Core (Core B) will support activities in all three Projects of this HIVRAD application. Specifically many of the reagents and assays that support the activities of all three Projects have been consolidated in this Core. In addition, all animal-related activities have been consolidated in this Core. Studies in nonhuman primates (rhesus macaques) will be conducted in the Washington National Primate Research Center (WaNPRC). The WaNPRC will provide comprehensive, efficient and safe conduct of the nonhuman primate-related portions of the HIVRAD Program including animal selection, research protocol implementation and execution, sample acquisition and distribution, animal care, and project budget administration. Immunizations of rabbits and mice will be performed under a 'fee-for-service'agreement with Pocono Rabbit Farm and Laboratory Inc. Hybridoma generation will be performed at Viro Dynamics, under a 'fee-for-service'agreement. Sera and monoclonal antibodies from the immunized animals will be analyzed for specificity and neutralizing activity.